Modular dewar system

ABSTRACT

An embodiment includes a modular dewar comprising a vacuum chamber, and a dewar circuit board. The dewar circuit board includes an inner portion including an electronic device positioned inside the vacuum chamber, an outer portion including electrical connectors positioned outside the vacuum chamber, and electrical traces connecting the electronic device inside the vacuum chamber to the electrical connectors outside the vacuum chamber.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Application No.62/416,253, filed Nov. 2, 2016. The contents of U.S. ProvisionalApplication No. 62/416,253 are incorporated by reference herein.

FIELD

The present invention relates to a modular dewar system for controllingthe temperature of electronic components.

BACKGROUND

Some electronic components generate a large amount of heat that must beextracted before they fail. One such example is an infrared lightemitting diode (IRLED) projector having an IRLED array and supportingelectronics. Conventional solutions for cooling the IRLED projectorinclude enclosing the IRLED array in vacuum sealed dewar. Refrigerant ispumped into a heat exchanger to cool the IRLED array.

These conventional solutions, however, are problematic due to theelectrical connections to the IRLED array. Due to the IRLED array beingenclosed in the dewar, the electrical connections and correspondingwires are also enclosed in the dewar. This requires that the electricalwires be routed from the IRLED array through the dewar to dedicatedelectrical connections penetrating the dewar that allow the internalwires to be electrically connected to external electronic devices (e.g.IRLED controller). Once the wires are routed through the dewar and theconnected to the dedicated electrical connections, this electricalconfiguration is fixed and cannot be easily altered. Therefore, theconventional dewar system is not easily reconfigured to supportdifferent electronic devices that need to be cooled (e.g. another LEDarray with different electrical requirements).

SUMMARY

An embodiment includes a modular dewar comprising a vacuum chamber, anda dewar circuit board. The dewar circuit board includes an inner portionincluding an electronic device positioned inside the vacuum chamber, anouter portion including electrical connectors positioned outside thevacuum chamber, and electrical traces connecting the electronic deviceinside the vacuum chamber to the electrical connectors outside thevacuum chamber.

Another embodiment includes a circuit board for cryo-packaging. Thecircuit board comprising an inner portion including an electronicdevice, the inner portion having a first predetermined geometry forpositioning inside a vacuum chamber, an outer portion includingelectrical connectors, the outer portion having a second predeterminedgeometry for positioning outside the vacuum chamber with the innerportion positioned inside a vacuum chamber, and electrical tracesconnecting the electronic device to the electrical connectors.

Yet another embodiment includes a modular dewar comprising a vacuumchamber defined by a front lid and a rear lid, an interposer comprisingan electrically insulating substrate having a first face in contact witha first vacuum seal in contact with the front lid and a second face incontact with a second vacuum seal in contact with the rear lid. Theinterposer comprising an inner portion positioned inside the vacuumchamber and containing a first electronic component, an outer portionpositioned outside the vacuum chamber and containing one or more secondelectronic components, and electrically conductive layers or members,and a temperature regulation device configured to cool the dewar,wherein the modular dewar is configured to permit exchanging the firstelectronic component for a second electronic component different thanthe first electronic component without requiring modifications to themodular dewar.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a view of an array of IRLEDs for projecting a pixelated image,according to an embodiment of the present invention.

FIG. 2 is a view of a system including the array of IRLEDs cryo-packagedin the modular dewar system, according to an embodiment of the presentinvention.

FIG. 3A is a side view of the modular dewar system in FIG. 2, accordingto an embodiment of the present invention.

FIG. 3B is an exploded view of the modular dewar system in FIG. 3A,according to an embodiment of the present invention.

FIG. 3C is a zoomed-in view of the head of the modular dewar system inFIG. 3A, according to an embodiment of the present invention.

FIG. 3D is side view of the IRLED array mounted to an interposer boardfor installation in the modular dewar system in FIG. 3A, according to anembodiment of the present invention.

FIG. 4A is a perspective view of another system including an array ofIRLEDs cryo-packaged in the modular dewar system, according to anembodiment of the present invention.

FIG. 4B is an exploded view of the modular dewar system in FIG. 4A,according to an embodiment of the present invention.

FIG. 5 is flowchart of assembling and operating the modular dewarsystem, according to an embodiment of the present invention.

DETAILED DESCRIPTION

Some electrical components may benefit from or require isolation fromthe ambient environment for various reasons (e.g. they may benefit froma temperature controlled environment). Vacuum sealing these componentsin a modular dewar is a solution to achieve this isolation.

Aspects of the present invention provides a method and system for vacuumsealing electronic components in a modular dewar to isolate thesecomponents from the ambient environment, while allowing convenientaccess to electrical connections if the components. Electricalcomponents that may benefit from or require vacuum sealing include butare not limited to emitter/detector systems and superconductorintegrated circuits (ICs) that require cooling for achieving lowoperating temperatures, infrared light emitting diodes (IRLEDs) thatrequire temperature regulation, IC chips that require temperature rangetesting, or components that may not require cooling/heating, but mayrequire isolation from the ambient environment.

An embodiment of the present invention provides a method and system forextracting heat from electronic components. The method and systemutilizes a cryo-packaging device including a modular dewar system havinga circuit board sized to be installed such that the electronic device isinside the modular dewar and the electrical connections to theelectronic device are outside the modular dewar.

FIG. 1 shows an example of electronic device 102 which is an infraredlight emitting diode (IRLED) array controlled by controller 104 (e.g.CPU) to project pixelated IR image 106. IRLED arrays may be used incertain applications (e.g. military applications). For example, missileguidance systems may include IR cameras to track the heat generated bytheir targets (e.g. enemy planes, vehicles, etc.). In order to assureaccuracy, it is beneficial to train these missile guidance systems byprojecting a pixelated image onto the IR camera, where the image is thencaptured an analysed. Thus, the IRLED array can be used to generate aheat signature of the target for the simulation.

During operation, the temperature of the IRLED increases, therebyemitting heat in the form of waste (e.g. radiated heat separate from theheat signature). To ensure that it operates correctly, the IRLED arraymust be sufficiently cooled to remove this waste heat. One such solutionis to install the IRLED array in a vacuum sealed dewar of a modulardewar system that is designed cool the IRLED array during operation(e.g. extract the waste heat). One example of such a modular dewarsystem is shown in FIG. 2.

FIG. 2 shows a modular dewar system for cooling the IRLED array in FIG.1 to maintain an appropriate operating temperature during thesimulation. The modular dewar system in FIG. 2 includes a cryo-packagingdevice 200 (e.g. vacuum sealed dewar and heat exchanger) for vacuumsealing and cooling the IRLED array, control electronics 104 forcontrolling the IRLED array, and a cooling system 204 including acompressor (not shown), refrigerant lines 208 and chilled water lines206 for extracting heat from the heat exchanger.

Prior to operation, the IRLED array is mounted and vacuum sealed insidea vacuum chamber of modular dewar 200. However, the electricalconnections to the IRLED array remain outside of the vacuum chamber, andare therefore easily accessible by the user. In general, this isaccomplished by installing the IRLED array in the center of a printedwiring board (e.g. FR4 PCB) where electrical traces internal to thecircuit board electrically connect the IRLED to external connectors(e.g. pins) installed on the outer periphery of the circuit board. Bymaking the circuit board larger than the geometry of the modular dewar,the IRLED array can be sealed within the modular dewar, while itselectrical connections can remain outside of the modular dewar. Furtherdetails of this feature are described in later figures.

Prior to operation, controller 102 for controlling the IRLED array isconnected via cable 202 (e.g. ribbon cable) to the electricalconnections of the IRLED array on the outer periphery of the circuitboard. Refrigerant lines 208 connect a compressor of cooling system 204to a heat exchanger of the modular dewar 200.

During operation, as the IRLED array is being controlled by controller104 to project an IR image through a window of the modular dewar, thesystem attempts to extract the heat generated by the IRLED array,thereby controlling its operating temperature. This is accomplished bymaintaining a vacuum inside the modular dewar and injecting, via thesource line of lines 208, refrigerant into a heat exchanger that isthermally coupled to the IRLED array through a cold head. Therefrigerant may be a liquid (e.g. R410A) or a gas (e.g. helium).

If the refrigerant is liquid, the heat accepted by the heat exchangerthrough the cold head extracts the heat by allowing the heat toevaporate the liquid refrigerant turning it into its gas phase. Theevaporated refrigerant travels through the return line of lines 208, isfurther compressed, and then pumped through a condenser where it iscooled back to a liquid state and then eventually pumped back into theheat exchanger for a further cooling cycle. This is a closed system forcontrolling the temperature of the IRLED array.

If the refrigerant is a gas, the heat accepted by the heat exchangerthrough the cold head extracts the heat by allowing the gas to absorbthe heat and expand. The expanded gas travels through the return line oflines 208 and is cooled. The cooled gas is eventually pumped back intothe heat exchanger for a further cooling cycle. This is a closed systemfor controlling the temperature of the IRLED array. Such systems arewell known in the art and need no further explanation.

A side view of an exemplary modular dewar 200 is shown in FIG. 3A.Dimensions shown relate to an exemplary embodiment, but the invention isnot limited to any particular dimensions of dewar or its componentparts. This side view shows that modular dewar 200 includes vacuumchamber 316 having window 304, lid 302, base 314 and vacuum port 322.Also included is heat exchanger 324 having refrigerant ports 326. Theheat exchanger is mechanically connected to vacuum chamber 316 viafasteners 320. It should be noted that the dimensions shown in FIG. 3Dare just one example of dimensions and geometry for a modular dewar.Other sizes, shapes and overall configurations are possible as long asthe IRLED 308 on circuit board 306 can be vacuum sealed, while theelectrical connections can be accessed outside of the vacuum seal.

FIG. 3B shows an exploded view of modular dewar 200 in FIG. 3A. In thisexample, modular dewar 200 has two primary parts including vacuumchamber 316 and heat exchanger 324 which are secured together withfasteners 320 (e.g. screws, bolts, etc.). Vacuum chamber 316 and heatexchanger 324 are thermally coupled to one another via cold head 312which runs axially through the inside of vacuum chamber 316 and into theheat exchanger 324. Vacuum chamber 316 is comprised of two partsincluding a base portion 314 having a bottom seal 318 and vacuum ports322 for connection to a vacuum generator, and a lid portion 302 having atop seal 302 (not shown) and window 304 for allowing the IR image to beprojected. Heat exchanger 324 may include internal fins (not shown) forextracting the heat from the modular dewar, and refrigerant ports 326for connection to the cooling device 204.

Also included is circuit board 306 (e.g. PCB board) including anelectronic device (e.g. IRLED array) mounted thereon, and one or moreelectrical connectors (e.g. pins) 310A-310D that are electricallyconnected to the IRLED array via traces (not shown) internal to circuitboard 306. In general, circuit board 306 is manufactured to havepredetermined geometry that positions IRLED array 308 inside of thevacuum chamber of modular dewar 200, while positioning electricalconnections 310A-310D outside the vacuum chamber.

In a first configuration, IRLED array 308 and electrical connections310A-310D are integral to circuit board 306. For example, IRLED array308 and electrical connections 310A-310D are mounted (e.g. soldered)directly on the traces of circuit board 306 during manufacturing. Insecond configuration, IRLED array 308 and electrical connections310A-310D are mounted on separate boards. For example, IRLED array 308is manufactured on a small IRLED array board, while a separate andlarger interposer board having a predetermined geometry is manufacturedto have electrical connections 310A-310D and internal traces. The IRLEDarray board and the interposer board in this second configuration arethen physically connected to each other (e.g. IRLED array board ismounted on the interposer board), and the IRLED array is electricallyconnected (e.g. IRLED array pins are soldered, wire bonded, or pluggedinto using a socket) to the traces in the interposer board, therebyelectrically connecting the IRLED array with the electrical connections.This second configuration may be beneficial when installing pre-existingIRLED arrays into modular dewar 200.

The predetermined geometry of circuit board 306 may be designed based onthe geometry of the vacuum chamber. For example, lid 302 and base 314form a vacuum chamber having a specific size (e.g. diameter and volume).The predetermined geometry of circuit board 306 is designed such thatthe IRLED array is positioned inside the geometry of the vacuum chamber,while the electrical connections are positioned outside the geometry ofthe vacuum chamber. For example, the IRLED array would be mounted insidethe known perimeter/volume of the vacuum chamber (e.g. inside theperimeter of seals 302/318), while the electrical connections would bemounted outside the known perimeter/volume of the vacuum chamber (e.g.outside the perimeter of seals 302/318).

During installation, board 306 including IRLED array 308 are positionedover base portion 318 of the modular dewar. The backside of IRLED array308, or a metal plate (not shown) thermally coupled to the back of theIRLED array 308 is positioned to come into physical contact with coldhead 312. IRLED array 308 may optionally be screwed to the cold head toensure this physical contact. Once seated on cold head 312, lid 302 ofthe modular dewar is positioned over the board such that fastener holesin lid 302, fastener holes in board 306 and fastener holes in base 314line up. Once the holes are aligned, fasteners (e.g. bolts, screws,etc.) are passed through the holes to sandwich board 306 in between lid302 and base 314. These fasteners are tightened to compress top seal(e.g. o-ring) 302 against the top surface of board 306, and compressbottom seal 318 (e.g. o-ring) against the bottom surface of board 306with enough force to create a vacuum seal in the chamber of the modulardewar. Thus, the respective areas of the circuit board that contact thetop seal and the bottom seal must be suitably smooth to hold a vacuumseal. In some embodiments, the respective areas may be polished and/ormay have an applied coating to make the respective areas relativelysmoother than surrounding areas of the circuit board for facilitatingthe seal, such as a coating of an elastomer, PTFE, a plastic, or thelike. In other embodiments, the entire circuit board may be constructedor coated with a material that provides a suitable level of smoothnessto maintain a desired vacuum and leakage rate. Surprisingly, it wasfound that sandwiching the electrical board (e.g. PCB) between lid 302and base 314 resulted in physical contact between the o-rings and theelectrical board surface that was sufficient to maintain a desiredvacuum and leakage rate within the dewar. Although depicted withfasteners that extend through the base portion 318 through board 306 andthrough lid 302, the invention is not limited to any particularstructure for generating the compressive force required to sandwich andposition the board between the respective seals in the base and lid.Thus, any number of structures may be employed, including “quickconnect” configurations that enable faster assembly than a traditionalnut and bolt assembly. In a configuration comprising fasteners extendingthrough the base portion 318 through board 306 and through lid 302, thefasteners are configured to receive a tensile force equal to thecompressive force required to sandwich the components together tomaintain the vacuum seal.

Although not shown, the o-rings may be replaced with other types ofseals. For example, indium wire, metal crush gaskets or solder jointsmay be used to create the vacuum seal. These types of seals may bebeneficial in higher vacuum applications that may not be suitable foruse of o-rings.

After the board is installed, electrical cables (not shown) areconnected to one of more of electrical connections 310A-310D such thatIRLED array is connected to other electronic devices (e.g. powersources, controllers, etc.). In addition, a vacuum hose is attached tovacuum port 322 and refrigerant lines are attached to refrigerant ports326.

Once installation is complete, the system may begin operation. Duringoperation (when IRLED array is operational and producing heat), acompressor attached to port 322 generates and maintains a vacuum inchamber 316, and a compressor attached to ports 326 pumps refrigerantthrough heat exchanger 324. Heat exchanger is thermally coupled to coldhead 312 which is thermally coupled to IRLED array 308. By “thermallycoupled” it is meant that the various components are disposed in arelationship with one another that facilitates heat transfer among thecomponents, such as through contact between thermally conductiveportions of the respective components in series, as optimized usingmaterials of construction and interfaces known in the field ofcryogenics. Thus, IRLED array 308 is thermally coupled to heat exchanger324 by cold head 312. Thus, heat produced by IRLED array 308 isconducted through cold head 312 and into heat exchanger 324 where it isthen extracted by the refrigerant.

A zoomed-in view of the top of modular dewar 200 in FIG. 3A is shown inFIG. 3C, where lid 302 having window 304 is mounted to the base (notshown) of the modular dewar such that circuit board 306 is sandwiched inbetween. IRLED (not shown) is vacuum sealed in the modular dewar andelectrically connected to the external electrical connection pins 310Aand 310D which allow for easy connection to other electronic devicessuch as the IRLED controller.

A cross-sectional view of the top of the modular dewar 200 in FIGS. 3Aand 3B is shown in FIG. 3D, where board 306 is shown to be sandwichedbetween modular dewar lid 302 and modular dewar base 312. A vacuum sealis produced by compressing seals (e.g. o-rings) 318 against the surfaceof board 306. Thus, an inner portion of board 306 that includes IRLEDarray 308 is vacuum sealed between lid 302 and base 314, whereas anouter portion of board 306 including electrical connectors 310A and 310Care not vacuum sealed between lid 302 and base 314. In this example,board 306 is implemented as an interposer board, where the smaller IRLEDboard is mounted on board 306 and electrically connected to the tracesof board 306 via connections 319. The electrical traces are not shown,because they run internal to board 306 to connect the IRLED connections319 to the external electrical connectors 310A and 310C.

FIG. 4A shows another example of a more compact modular dewar. In thisexample, the modular dewar includes a vacuum chamber comprised of basepart 404 and lid part 402 having a window 408. Circuit board 410 havingthe IRLED array is sandwiched between lid part 402 and base part 404such that portions 410A-410D of the circuit board 410 are positionedoutside of the vacuum chamber. Although not shown, the electricalconnectors are positioned on one or more of portions 410A-410D.

An exploded view of the modular dewar in FIG. 4A is shown in FIG. 4B. Asshown, lid 402 may be comprised of multiple parts including lid part402A and lid part 402C. The window may be a piece of glass 402B that issandwiched between lid parts 402A and 402C with seal 412B to ensure thevacuum seal integrity. Parts 404, 410, 402A and 402C all have holes toaccept fasteners. To install board 410, fasteners are inserted throughthe aligned holes of parts 404, 410, 402A and 402C, such that window iscompressed against seal 412B and circuit board 410 is compressed againstbottom seal 412A and a top seal (not shown) on the back of part 402A,although, as noted above, the invention is not limited to the use ofthreaded fasteners inserted through holes in the subject parts forderiving the requisite compressive force. In addition, mounting base 406may also be provided for standing modular dewar upright duringoperation. Mounting base 406 may also be connected to base part 404 viaa hinge (not shown) so that the IRLED can be angled during operation.

An example of the operation of modular dewar system is described in theflowchart of FIG. 5. In step 502, a circuit board having a predeterminedgeometry is fabricated. This circuit board includes electrical tracesconnecting a central portion of the board to electrical connectorsmounted on the periphery of the board. In step 504, the IRLED array caneither be fabricated on the circuit board or mounted to the circuitboard at a later time. In either scenario, the IRLED array iselectrically connected to the traces of the circuit board. In step 506,the circuit board is mounted in the vacuum chamber of the modular dewarsuch that the IRLED array is vacuum sealed in the chamber and theelectrical connectors are positioned outside of the chamber. In step508, the controller for controlling the IRLED array is connected to theelectrical connectors, the vacuum pump is connected to the vacuum portvia a hose, and the coolant system is connected to the refrigerant portsvia hoses. Once the connections are made, in step 510, the systemincluding the IRLED array, vacuum pump and cooling system are poweredON. During operation of the IRLED array, the temperature is monitoredvia a temperature sensor (not shown). This temperature may be used tocontrol the ON/OFF cycle of the cooling system.

Although the figures and description show and describe the cooling of anIRLED array, it should be noted that any electronic device thatgenerates heat may be cryo-packaged and cooled in the modular dewar. Forexample, power electronics that generate heat may be cryo-packaged andcooled in the modular dewar in a similar manner. It should also be notedthat rather than cooling the electronic components, the modular dewarsystem may be used to heat the components. For example, if theelectronics are to be installed in an extreme cold climate location, theheat exchanger and cooling system of the cryo-packaging system can beredesigned to provide heat to the vacuum sealed electronic device (e.g.hot liquid is pumped through the heat exchanger). This protects theelectronic device from the extreme cold ambient temperatures at theinstallation location. It should also be noted that the modular dewarsystem may not include a heat exchanger. The modular dewar system maycomprise a vacuum chamber used to isolate the components from theambient environment without providing additional cooling/heating. Thismay be useful in applications where electronic components may requireisolation from contaminants and extreme ambient temperatures.

The method/system for vacuum sealing electronic components avoids thestructural limitations of conventional dewars that have a fixed numberof ceramic or glass electrical feedthroughs and electrical plug-ins forrouting electrical wires and accessing the electrical connections to thechip under test. These feedthroughs are installed during manufacturingand take up valuable space which increases the overall size of thedewar. The number of electrical connections to the electronic device arealso limited by the number of feedthroughs provided. In contrast, thepresent invention allows chips and their PCBs to be installed in thedewar without using the electrical feedthroughs. Therefore, in thepresent invention, the technician can swap out chips under test andtheir PCBs without being limited to the fixed number of electricalplug-ins related to the dewar construction.

Although the invention is illustrated and described herein withreference to specific embodiments, the invention is not intended to belimited to the details shown. Rather various modifications may be madein the details within the scope and range of equivalence of the claimsand without departing from the invention.

1. A modular dewar comprising: a vacuum chamber; and a dewar circuitboard including: an inner portion including an electronic devicepositioned inside the vacuum chamber, an outer portion includingelectrical connectors positioned outside the vacuum chamber, andelectrical traces connecting the electronic device inside the vacuumchamber to the electrical connectors outside the vacuum chamber.
 2. Themodular dewar of claim 1, further comprising: a base portion and a lidportion that define the vacuum chamber a first seal interposed betweenthe base portion and a first face of the dewar circuit board; a secondseal interposed between the lid portion and a second face of the dewarcircuit board, wherein the first seal and the second seal define avacuum seal between the inner portion of the dewar circuit board and theouter portion of the dewar circuit board.
 3. The modular dewar of claim2, wherein the first seal and the second seal are o-rings.
 4. Themodular dewar of claim 2, wherein the base portion, the first seal, thedewar circuit board, the second seal and the lid portion are secured ina compressive relationship with one another by a compressive force. 5.The modular dewar of claim 2, further comprising: fasteners that passthrough the lid portion, the dewar circuit board and the base portion togenerate the compressive force.
 6. The modular dewar of claim 1, furthercomprising: a heat exchanger thermally coupled to the electronic deviceand configured to extract heat from the electronic device; and a coldhead thermally coupled to the electronic device and the heat exchangerand configured to transfer the heat from the electronic device to theheat exchanger.
 7. The modular dewar of claim 1, further comprising: aheat exchanger thermally coupled to the electronic device and configuredto extract heat from the electronic device, wherein the heat exchangeris a component in a vapor-compression refrigeration system having inputand output ports connecting the heat exchanger to a compressor viarefrigerant lines.
 8. The modular dewar of claim 1, wherein theelectronic device is embedded in the dewar circuit board.
 9. The modulardewar of claim 1, wherein the electronic device is embedded in a carriercircuit board that is electrically connected to the dewar circuit board.10. The modular dewar of claim 1, wherein the electronic devicecomprises an infrared light emitting diode (IRLED) array.
 11. A circuitboard for cryo-packaging, the circuit board comprising: an inner portionincluding an electronic device, the inner portion having a firstpredetermined geometry for positioning inside a vacuum chamber; an outerportion including electrical connectors, the outer portion having asecond predetermined geometry for positioning outside the vacuum chamberwith the inner portion positioned inside a vacuum chamber; andelectrical traces connecting the electronic device to the electricalconnectors.
 12. The circuit board for cryo-packaging of claim 11,further comprising: a top surface having an area configured to contact afirst seal of the vacuum chamber; and a bottom surface having an areaconfigured to contact a second seal of the vacuum chamber, wherein therespective areas of the top surface and the bottom surface areconfigured to be held in contact with the first and second seal bycompressive force suitable to vacuum seal the inner portion of thecircuit board inside the vacuum chamber.
 13. The circuit board forcryo-packaging of claim 12, wherein the top surface area and bottomsurface area configured to contact the first seal and second seal areconstructed to retain vacuum.
 14. The circuit board for cryo-packagingof claim 11, wherein the electrical traces are positioned internal tothe circuit board.
 15. The circuit board for cryo-packaging of claim 12,further comprising: fasteners locations on the outer portion of thecircuit board for receiving fasteners for bearing a tensile force equalto the compressive force for holding the first seal and second seal incontact with the circuit board.
 16. The circuit board for cryo-packagingof claim 11, wherein the electrical connectors are pin connectors. 17.The circuit board for cryo-packaging of claim 11, further comprising: athermal contact surface positioned below the electronic device tothermally couple the electronic device to a heat exchanger.
 18. Thecircuit board for cryo-packaging of claim 11, wherein the electronicdevice is embedded in the circuit board.
 19. The circuit board forcryo-packaging of claim 11, wherein the circuit board is a first circuitboard and the electronic device comprises a separate, second circuitboard electrically connected to the first circuit board.
 20. The circuitboard for cryo-packaging of claim 11, wherein the electronic devicecomprises an infrared light emitting diode (IRLED) array.
 21. A modulardewar comprising: a vacuum chamber defined by a front lid and a rearlid; an interposer comprising an electrically insulating substratehaving a first face in contact with a first vacuum seal in contact withthe front lid and a second face in contact with a second vacuum seal incontact with the rear lid, the interposer comprising: an inner portionpositioned inside the vacuum chamber and containing a first electroniccomponent, an outer portion positioned outside the vacuum chamber andcontaining one or more second electronic components, and electricallyconductive layers or members; and a temperature regulation deviceconfigured to cool the dewar, wherein the modular dewar is configured topermit exchanging the first electronic component for a second electroniccomponent different than the first electronic component withoutrequiring modifications to the modular dewar.